´It was narrated from 'Abdullah bin 'Abdullah bin 'Umar that his father said:` "One of the sunnahs of the prayer is to spread your left foot beneath you, and hold your right foot upright."
Hadith Referenceسنن نسائي / كتاب التطبيق / 1158
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح بخاري